Go to Tools > Internet Options > Security tab
Then select Trusted Sites > Sites button
In the Trusted Sites dialog box: type in the URL of the site you want to add > Add > Close.
Open the Google Chrome hamburger menu (which looks like 3 horizontal lines in the corner of the screen):
Select the Settings link, then scroll down to the link Show Advanced Settings...
Select: Proxy settings > Security tab > Trusted Sites > Sites
Enter the URL of the site you want to add > Add > Close
Firefox has different areas where exceptions need to be added depending on what kind of exceptions you wish to make.
Settings > Content
To allow a site to use pop up windows, click on Exceptions and add the URL of the site you wish to allow.
To allow a site to load images, click Exceptions > Allow.
To bypass the warning certificate, click I understand the risks > Add Exception > Confirm Security Exception.